Inrush flow-free switching device and control method thereof

Abstract

The invention discloses an inrush flow-free switching device and a control method thereof, and belongs to the electric field, and discloses the inrush flow-free switching device especially suitable for switching of capacitors and other capacitive loads, and the control method thereof. The inrush flow-free switching device comprises a mechanical switch, a first unidirectional thyristor, a second unidirectional thyristor, a control unit, and a limiting element. The first unidirectional thyristor is serially connected with the limiting element to form a serial connection circuit. The serial connection circuit is parallely connected with the second unidirectional thyristor, and the two ends of the main circuit of the mechanical switch are parallely connected with the second unidirectional thyristor. The control unit is connected with the control end of the mechanical switch, and is connected with the first unidirectional thyristor and the second unidirectional thyristor. The motion time parameters of the mechanical switch are pre-stored in the control unit. The inrush flow-free switching device has advantages of short conduction time of thyristors, strong overload capability, high cost performance, long electric service lifetime of mechanical switch, and high reliability.

Description

technical field [0001] The invention relates to a non-inrush switching device and a control method thereof, belonging to the electrical field, in particular to a non-inrush switching device suitable for switching capacitive loads such as capacitors and a control method thereof. Background technique [0002] At present, in electrical control systems, non-inrush switching devices such as composite switches are widely used to control power capacitors and other loads on and off. It uses two unidirectional thyristors connected in reverse parallel and then connected with mechanical switches (magnetic latching relays and other electromagnetic switches) ) in parallel, during the connection process, the control unit first controls two unidirectional thyristors to conduct at zero crossing before the mechanical switch is closed, and then controls the mechanical switch to close. The existing composite switch has the following disadvantages: [0003] 1. Due to the capacitive load, it is...

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Problems solved by technology

[0006] The purpose of the present invention is to provide a non-surge switching device with short thyristor conduction time, strong overload capacity, high cost performance, long electrical life of mechanical switch and high reliability in view of the shortcomings of existing composite switches and other non-surge switching devices. Switching device and its control method

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